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1.
Am J Obstet Gynecol ; 225(1): 79.e1-79.e13, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33460583

RESUMO

BACKGROUND: In singleton pregnancies, studies investigating cell-free DNA in maternal blood have consistently reported high detection rate and low false-positive rate for the 3 common fetal trisomies (trisomies 21, 18, and 13). The potential advantages of noninvasive prenatal testing in twin pregnancies are even greater than in singletons, in particular lower need for invasive testing and consequent fetal loss rate. However, several organizations do not recommend cell-free DNA in twin pregnancies and call for larger prospective studies. OBJECTIVE: In response to this, we undertook a large prospective multicenter study to establish the screening performance of cell-free DNA for the 3 common trisomies in twin pregnancies. Moreover, we combined our data with that reported in published studies to obtain the best estimate of screening performance. STUDY DESIGN: This was a prospective multicenter blinded study evaluating the screening performance of cell-free DNA in maternal plasma for the detection of fetal trisomies in twin pregnancies. The study took place in 6 fetal medicine centers in England, United Kingdom. The primary outcome was the screening performance and test failure rate of cell-free DNA using next generation sequencing (the IONA test). Maternal blood was taken at the time of (or after) a conventional screening test. Data were collected at enrolment, at any relevant invasive testing throughout pregnancy, and after delivery until the time of hospital discharge. Prospective detailed outcome ascertainment was undertaken on all newborns. The study was undertaken and reported according to the Standards for Reporting of Diagnostic Accuracy Studies. A pooled analysis was also undertaken using our data and those in the studies identified by a literature search (MEDLINE, Embase, CENTRAL, Cochrane Library, and ClinicalTrials.gov) on June 6, 2020. RESULTS: A total of 1003 women with twin pregnancies were recruited, and complete data with follow-up and reference data were available for 961 (95.8%); 276 were monochorionic and 685 were dichorionic. The failure rate was 0.31%. The mean fetal fraction was 12.2% (range, 3%-36%); all 9 samples with a 3% fetal fraction provided a valid result. There were no false-positive or false-negative results for trisomy 21 or trisomy 13, whereas there was 1 false-negative and 1 false-positive result for trisomy 18. The IONA test had a detection rate of 100% for trisomy 21 (n=13; 95% confidence interval, 75-100), 0% for trisomy 18 (n=1; 95% confidence interval, 0-98), and 100% for trisomy 13 (n=1; 95% confidence interval, 3-100). The corresponding false-positive rates were 0% (95% confidence interval, 0-0.39), 0.10% (95% confidence interval, 0-0.58), and 0% (95% confidence interval, 0-0.39), respectively. By combining data from our study with the 11 studies identified by literature search, the detection rate for trisomy 21 was 95% (n=74; 95% confidence interval, 90-99) and the false-positive rate was 0.09% (n=5598; 95% confidence interval, 0.03-0.19). The corresponding values for trisomy 18 were 82% (n=22; 95% confidence interval, 66-93) and 0.08% (n=4869; 95% confidence interval, 0.02-0.18), respectively. There were 5 cases of trisomy 13 and 3881 non-trisomy 13 pregnancies, resulting in a computed average detection rate of 80% and a false-positive rate of 0.13%. CONCLUSION: This large multicenter study confirms that cell-free DNA testing is the most accurate screening test for trisomy 21 in twin pregnancies, with screening performance similar to that in singletons and very low failure rates (0.31%). The predictive accuracy for trisomies 18 and 13 may be less. However, given the low false-positive rate, offering first-line screening with cell-free DNA to women with twin pregnancy is appropriate in our view and should be considered a primary screening test for trisomy 21 in twins.


Assuntos
Ácidos Nucleicos Livres/sangue , Testes para Triagem do Soro Materno/métodos , Teste Pré-Natal não Invasivo/métodos , Gravidez de Gêmeos/genética , Adulto , Síndrome de Down/diagnóstico , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Estudos Prospectivos , Sensibilidade e Especificidade , Síndrome da Trissomia do Cromossomo 13/diagnóstico , Síndrome da Trissomía do Cromossomo 18/diagnóstico
2.
J Obstet Gynaecol ; 39(3): 328-334, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30714504

RESUMO

Molecular diagnostic investigations, following the identification of foetal abnormalities, are routinely performed using array comparative genomic hybridisation (aCGH). Despite the utility of this technique, contemporary approaches for the detection of copy number variation are typically based on next-generation sequencing (NGS). We sought to compare an in-house NGS-based workflow (CNVseq) with aCGH, for invasively obtained foetal samples from pregnancies complicated by foetal structural abnormality. DNA from 40 foetuses was screened using both 8 × 60 K aCGH oligoarrays and low-coverage whole genome sequencing. Sequencer-compatible libraries were combined in a ten-sample multiplex and sequenced using an Illumina HiSeq2500. The mean resolution of CNVseq was 29 kb, compared to 60 kb for aCGH analyses. Four clinically significant, concordant, copy number imbalances were detected using both techniques, however, genomic breakpoints were more precisely defined by CNVseq. This data indicates CNVseq is a robust and sensitive alternative to aCGH, for the prenatal investigation of foetuses with structural abnormalities. Impact statement What is already known about this subject? Copy number variant analysis using next-generation sequencing has been successfully applied to investigations of tumour specimens and patients with developmental delays. The application of our approach, to a prospective prenatal diagnosis cohort, has not hitherto been assessed. What do the results of this study add? Next-generation sequencing has a comparable turnaround time and assay sensitivity to copy number variant analysis performed using array CGH. We demonstrate that having established a next-generation sequencing facility, high-throughput CNVseq sample processing and analysis can be undertaken within the framework of a regional diagnostic service. What are the implications of these findings for clinical practice and/or further research? Array CGH is a legacy technology which is likely to be superseded by low-coverage whole genome sequencing, for the detection of copy number variants, in the prenatal diagnosis of structural abnormalities.


Assuntos
Hibridização Genômica Comparativa/normas , Variações do Número de Cópias de DNA , Sequenciamento de Nucleotídeos em Larga Escala/normas , Diagnóstico Pré-Natal/métodos , Feminino , Humanos , Gravidez , Estudos Prospectivos
3.
Bipolar Disord ; 19(4): 259-272, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28574156

RESUMO

OBJECTIVES: Individualized treatment for bipolar disorder based on neuroimaging treatment targets remains elusive. To address this shortcoming, we developed a linguistic machine learning system based on a cascading genetic fuzzy tree (GFT) design called the LITHium Intelligent Agent (LITHIA). Using multiple objectively defined functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy (1 H-MRS) inputs, we tested whether LITHIA could accurately predict the lithium response in participants with first-episode bipolar mania. METHODS: We identified 20 subjects with first-episode bipolar mania who received an adequate trial of lithium over 8 weeks and both fMRI and 1 H-MRS scans at baseline pre-treatment. We trained LITHIA using 18 1 H-MRS and 90 fMRI inputs over four training runs to classify treatment response and predict symptom reductions. Each training run contained a randomly selected 80% of the total sample and was followed by a 20% validation run. Over a different randomly selected distribution of the sample, we then compared LITHIA to eight common classification methods. RESULTS: LITHIA demonstrated nearly perfect classification accuracy and was able to predict post-treatment symptom reductions at 8 weeks with at least 88% accuracy in training and 80% accuracy in validation. Moreover, LITHIA exceeded the predictive capacity of the eight comparator methods and showed little tendency towards overfitting. CONCLUSIONS: The results provided proof-of-concept that a novel GFT is capable of providing control to a multidimensional bioinformatics problem-namely, prediction of the lithium response-in a pilot data set. Future work on this, and similar machine learning systems, could help assign psychiatric treatments more efficiently, thereby optimizing outcomes and limiting unnecessary treatment.


Assuntos
Sintomas Comportamentais , Transtorno Bipolar , Resistência a Medicamentos , Compostos de Lítio , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Adolescente , Adulto , Antimaníacos/administração & dosagem , Antimaníacos/efeitos adversos , Inteligência Artificial , Sintomas Comportamentais/diagnóstico , Sintomas Comportamentais/tratamento farmacológico , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/psicologia , Manual Diagnóstico e Estatístico de Transtornos Mentais , Monitoramento de Medicamentos/métodos , Feminino , Lógica Fuzzy , Humanos , Compostos de Lítio/administração & dosagem , Compostos de Lítio/efeitos adversos , Masculino , Imagem Multimodal/métodos , Projetos Piloto , Valor Preditivo dos Testes , Prognóstico
4.
Prenat Diagn ; 37(10): 1001-1007, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28753246

RESUMO

OBJECTIVE: To describe data on congenital lung anomalies identified on prenatal ultrasound from two centres in the North of England. METHOD: This retrospective case series includes all cases notified to the Northern Congenital Abnormality Survey from 1990 to 2010 and to Leeds Regional Fetal Medicine Unit 2000-2015. RESULTS: There were a total of 228 cases, 101 from Northern Congenital Abnormality Survey and 127 from Leeds Regional Fetal Medicine Unit. Eight-five per cent were unilateral congenital pulmonary airway malformations (CPAMs), 2% bilateral CPAMs and 11% bronchopulmonary sequestrations. Mediastinal shift was present in 50% of cases, occurring more frequently in macrocystic CPAMs and larger lesions. Polyhydramnios was evident in 28%, and fetal hydrops occurred in 9%. Prenatal regression occurred in 54%, and lesions were no longer visible on ultrasound in 27% at a later gestation. Prenatal intervention was performed in 5% of cases, and postnatal surgical intervention was required in 12% due to ongoing respiratory symptoms. Regression of fetal hydrops occurred in five cases. CONCLUSION: The outcome was favourable in 83% cases. Prenatal regression was common, and macrocystic lesions were less likely to regress than microcystic lesions. No specific prenatal features predicted the need for early surgical intervention. The data analysed in this prenatal series will help when counselling prenatal cases. © 2017 John Wiley & Sons, Ltd.


Assuntos
Doenças Fetais/diagnóstico por imagem , Anormalidades do Sistema Respiratório/diagnóstico por imagem , Anormalidades do Sistema Respiratório/embriologia , Aconselhamento , Inglaterra , Feminino , Idade Gestacional , Humanos , Pulmão/anormalidades , Pulmão/diagnóstico por imagem , Pulmão/embriologia , Gravidez , Resultado da Gravidez , Cuidado Pré-Natal/métodos , Prognóstico , Estudos Retrospectivos , Ultrassonografia Pré-Natal
6.
J Phys Chem C Nanomater Interfaces ; 128(6): 2625-2633, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38379919

RESUMO

Anion engineering has proven to be an effective strategy to tailor the physical and chemical properties of metal oxides by modifying their existing crystal structures. In this work, a low-temperature synthesis for rare earth (RE)-doped Y2O2SO4 and Y2O2S was developed via annealing of Y(OH)3 intermediates in the presence of elemental sulfur in a sealed tube, followed by a controlled reduction step. The crystal structure patterns (X-ray diffraction) and optical spectra (UV-IR) of Y2O2SO4, Y2O2S, and crystalline Y2O3 were collected throughout the treatment steps to correlate the structural transformations (via thermogravimetric analysis) with the optical properties. Local and long-range crystallinities were characterized by using X-ray and optical spectroscopy approaches. Systematic shifts in the Eu3+ excitation and emission peaks were observed as a function of SO42- and S2- concentrations resulting from a crystal evolution from cubic (Y2O3) to trigonal (Y2O2S) and monoclinic (Y2O2SO4), which can modify the local hybridization of sensitizer dopants (i.e., Ce3+). Ultimately, Tb3+ and Tb3+/Ce3+ doping was employed in these hosts (Y2O2SO4, Y2O2S, and Y2O3) to understand energy transfer between sensitizer and activator ions, which showed significant enhancement for the monoclinic sulfate structure.

7.
J Clin Exp Neuropsychol ; 45(3): 242-254, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37278690

RESUMO

INTRODUCTION: While pain self-management programs can significantly improve patient outcomes, poor adherence is common and the need for research on predictors of adherence has been noted. A potential, but commonly overlooked, predictor is cognitive function. Our aim, then, was to examine the relative influence of various cognitive functional domains on engagement with an online pain self-management program. METHOD: A secondary analysis of a randomized controlled trial testing the impact of E-health (a 4-month subscription to the online Goalistics Chronic Pain Management Program) plus treatment as usual, relative to treatment as usual alone, on pain and opioid dose outcomes in adults receiving long-term opioid therapy of morphine equivalence dose ≥20 mg; 165 E-health participants who completed an on-line neurocognitive battery were included in this sub-analysis. A variety of demographic, clinical, and symptom rating scales were also examined. We hypothesized that better processing speed and executive functions at baseline would predict engagement with the 4-month E-health subscription. RESULTS: Ten functional cognitive domains were identified using exploratory factor analysis and the resultant factor scores applied for hypothesis testing. The strongest predictors of E-health engagement were selective attention, and response inhibition and speed domains. An explainable machine learning algorithm improved classification accuracy, sensitivity, and specificity. CONCLUSIONS: The results suggest that cognition, especially selective attention, inhibitory control, and processing speed, is predictive of online chronic pain self-management program engagement. Future research to replicate and extend these findings seems warranted. CLINICALTRIALS.GOV REGISTRATION NUMBER: NCT03309188.


Assuntos
Dor Crônica , Autogestão , Adulto , Humanos , Manejo da Dor/métodos , Analgésicos Opioides/uso terapêutico , Dor Crônica/tratamento farmacológico , Dor Crônica/psicologia
8.
Complex Eng Syst ; 2(4)2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37025127

RESUMO

This paper presents the use of two popular explainability tools called Local Interpretable Model-Agnostic Explanations (LIME) and Shapley Additive exPlanations (SHAP) to explain the predictions made by a trained deep neural network. The deep neural network used in this work is trained on the UCI Breast Cancer Wisconsin dataset. The neural network is used to classify the masses found in patients as benign or malignant based on 30 features that describe the mass. LIME and SHAP are then used to explain the individual predictions made by the trained neural network model. The explanations provide further insights into the relationship between the input features and the predictions. SHAP methodology additionally provides a more holistic view of the effect of the inputs on the output predictions. The results also present the commonalities between the insights gained using LIME and SHAP. Although this paper focuses on the use of deep neural networks trained on UCI Breast Cancer Wisconsin dataset, the methodology can be applied to other neural networks and architectures trained on other applications. The deep neural network trained in this work provides a high level of accuracy. Analyzing the model using LIME and SHAP adds the much desired benefit of providing explanations for the recommendations made by the trained model.

9.
Methods Mol Biol ; 2393: 877-903, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34837217

RESUMO

The best predictor of future injury is previous injury and this has not changed in a quarter century despite the introduction of evidence-based medicine and associated revisions to post-injury treatment and care. Nearly nine million sports-related injuries occur annually, and the majority of these require medical intervention prior to clearance for the athlete to return to play (RTP). Regardless of formal care, these athletes remain two to four times more likely to suffer a second injury for several years after RTP. In the case of children and young adults, this sets them up for a lifetime of negative health outcomes. Thus, the initial injury is the tipping point for a post-injury cascade of negative sequelae exposing athletes to more physical and psychological pain, higher medical costs, and greater risk of severe long-term negative health throughout their life. This chapter details the technologies and method that make up the automated Intelligent Phenotypic Plasticity Platform (IP3)-a revolutionary new approach to the current standard of post-injury care that identifies and targets deficits that underly second injury risk in sport. IP3 capitalizes on the biological concept of phenotypic plasticity (PP) to quantify an athlete's functional adaptability across different performance environments, and it is implemented in two distinct steps: (1) phenomic profiling and (2) precision treatment. Phenomic profiling indexes the fitness and subsequent phenotypic plasticity of an individual athlete, which drives the personalization of the precision treatment step. IP3 leverages mixed-reality technologies to present true-to-life environments that test the athlete's ability to adapt to dynamic stressors. The athlete's phenotypic plasticity profile is then used to drive a precision treatment that systematically stresses the athlete, via a combination of behavioral-based and genetic fuzzy system models, to optimally enhance the athlete's functional adaptability. IP3 is computationally light-weight and, through the integration with mixed-reality technologies, promotes real-time prediction, responsiveness, and adaptation. It is also the first ever phenotypic plasticity-based precision medicine platform, and the first precision sports medicine platform of any kind.


Assuntos
Medicina de Precisão , Adaptação Fisiológica , Traumatismos em Atletas/prevenção & controle , Criança , Humanos , Relesões , Esportes , Adulto Jovem
10.
J Neurotrauma ; 38(7): 830-836, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33115345

RESUMO

This pilot study explores the possibility of predicting post-concussion symptom recovery at one week post-injury using only objective diffusion tensor imaging (DTI) data inputs to a novel artificial intelligence (AI) system composed of Genetic Fuzzy Trees (GFT). Forty-three adolescents age 11 to 16 years with either mild traumatic brain injury or traumatic orthopedic injury were enrolled on presentation to the emergency department. Participants received a DTI scan three days post-injury, and their symptoms were assessed by the Post-Concussion Symptom Scale (PCSS) at 6 h and one week post-injury. The GFT system was trained using one-week total PCSS scores, 48 volumetric magnetic resonance imaging inputs, and 192 DTI inputs per participant over 225 training runs. Each training run contained a randomly selected 80% of the total sample followed by a 20% validation run. Over a different randomly selected sample distribution, GFT was also compared with six common classification methods. The cascading GFT structure controlled an effectively infinite solution space that classified participants as recovered or not recovered significantly better than chance. It demonstrated 100% and 62% classification accuracy in training and validation, respectively, better than any of the six comparison methods. Recovery sensitivity and specificity were 59% and 65% in the GFT validation set, respectively. These results provide initial evidence for the effectiveness of a GFT system to make clinical predictions of trauma symptom recovery using objective brain measures. Although clinical and research applications will necessitate additional optimization of the system, these results highlight the future promise of AI in acute care.


Assuntos
Inteligência Artificial/tendências , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Síndrome Pós-Concussão/diagnóstico por imagem , Recuperação de Função Fisiológica/fisiologia , Adolescente , Criança , Estudos de Coortes , Feminino , Lógica Fuzzy , Humanos , Masculino , Projetos Piloto , Síndrome Pós-Concussão/genética , Valor Preditivo dos Testes , Estudos Prospectivos
11.
Front Robot AI ; 7: 601243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33501362

RESUMO

This paper introduces a new genetic fuzzy based paradigm for developing scalable set of decentralized homogenous robots for a collaborative task. In this work, the number of robots in the team can be changed without any additional training. The dynamic problem considered in this work involves multiple stationary robots that are assigned with the goal of bringing a common effector, which is physically connected to each of these robots through cables, to any arbitrary target position within the workspace of the robots. The robots do not communicate with each other. This means that each robot has no explicit knowledge of the actions of the other robots in the team. At any instant, the robots only have information related to the common effector and the target. Genetic Fuzzy System (GFS) framework is used to train controllers for the robots to achieve the common goal. The same GFS model is shared among all robots. This way, we take advantage of the homogeneity of the robots to reduce the training parameters. This also provides the capability to scale to any team size without any additional training. This paper shows the effectiveness of this methodology by testing the system on an extensive set of cases involving teams with different number of robots. Although the robots are stationary, the GFS framework presented in this paper does not put any restriction on the placement of the robots. This paper describes the scalable GFS framework and its applicability across a wide set of cases involving a variety of team sizes and robot locations. We also show results in the case of moving targets.

12.
Genet Mol Biol ; 32(1): 96-103, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21637652

RESUMO

The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 µg.g (-1) , and ranged from 1.06 µg.g (-1) for the triploid Nanica (Cavendish group) to 19.24 µg.g (-1) for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 µg.g (-1)). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.

13.
Eur J Obstet Gynecol Reprod Biol ; 237: 89-92, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31035121

RESUMO

OBJECTIVE: The prevalence of red cell antibodies in pregnancy varies with ethnicity and geographical location, while the obstetric outcome depends on the available standard of care. Despite being the tertiary fetal medicine centre in West Yorkshire, the prevalence of red cell antibodies, and the outcome of pregnancies associated with these antibodies at the Leeds University Teaching Hospitals Trust remains unreported. This article aims to provide this information for the purpose of patient education and counselling. STUDY DESIGN: The data of pregnant women with red cell antibodies between January 2011 and December 2016 was obtained from the Trust's database and reconciled with the Fetal Medicine Unit records using Viewpoint©. Fetal anaemia requiring in utero transfusion (IUT) was defined as a Middle Cerebral Artery Peak Systolic Velocities ≥ 1.5multiple of the median expected for gestational age. The mean gestational age at delivery, and perinatal outcomes of the pregnancies were recorded. RESULT: Overall, 398 of the 96, 692 pregnant women that were screened had red cell antibodies, giving a prevalence of 1: 242 pregnancies. The Anti- E and Anti-M antibodies were the most common (114 women; 28.6%, and 112 women; 28.1% respectively), but did not cause fetal anaemia in isolation, while anti-D alloimmunization was the predominant indication for in-utero transfusion (IUT). Anti-DE and anti-Kell antibodies had the highest mean number of transfusions per pregnancy. The mean gestational age at delivery was 34 ± 2weeks. Post-transfusion fetal demise was recorded in two hydropic fetuses, both at a gestational age of 25 weeks; giving a transfusion-related mortality rate of 2.5%. CONCLUSION: The prevalence of red cell antibodies at West Yorkshire is lower compared with reports from other Caucasian populations.Nevertheless, these antibodies are important causes of iatrogenic preterm delivery and fetal morbidity. The prognosis is however good with prompt diagnosis and management.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Autoanticorpos , Isoimunização Rh/epidemiologia , Sistema do Grupo Sanguíneo Rh-Hr/imunologia , Adulto , Inglaterra , Feminino , Idade Gestacional , Hospitais de Ensino , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez , Prevalência
14.
Acta amaz ; 41(2): 279-284, 2011. tab
Artigo em Português | LILACS, VETINDEX | ID: lil-586484

RESUMO

A etapa de fermentação na produção da farinha de mandioca do grupo d'água é responsável pelo desenvolvimento de características químicas e sensoriais peculiares no produto. O objetivo deste estudo foi verificar a influência da etapa de fermentação das raízes de mandioca nos principais parâmetros físico-químicos da farinha, seguido de avaliação sensorial da preferência do consumidor. As análises realizadas foram determinação do teor de umidade, cinzas, proteínas, amido e acidez total titulável. O teste sensorial utilizado foi o de ordenação-preferência dos produtos. De acordo com os resultados obtidos, a etapa de fermentação, responsável pelo aumento da acidez total titulável da farinha de mandioca do grupo d'água, foi o único parâmetro que excedeu o valor limite permitido pela legislação brasileira vigente. Com base no resultado da análise sensorial, houve maior preferência dos consumidores pela farinha de mandioca com maior teor de acidez total (3,44 cmol NaOH kg-1), que corresponde à raiz fermentada por 96 horas.


The fermentation stage in the production of fermented cassava flour (also known as farinha d'água in Brazil) is responsible for the development of chemical and sensorial characteristics in the product. Thus the aim of this study was to verify the influence of the fermentation stage in the flour's main physicochemical parameters, followed by sensory evaluation of customer preference. The analyses performed were moisture, ash, protein, starch amounts and total acidity. The sensory analysis of the produced flour was performed using the preference-ordering test. According to the results, the fermentation stage, responsible for the increase of total acidity content in the final product, was the only parameter which exceeds the value demanded by Brazilian legislation. Based on the result of sensorial analysis, most customers preferred cassava flour with the highest amount of total acidity (3.44 cmol NaOH kg-1), which correspond to the root fermented for 96 hours.


Assuntos
Manihot , Acidez
15.
Rev. Inst. Adolfo Lutz ; 70(1): 41-46, jan.-mar. 2011. tab, graf
Artigo em Português | LILACS, SES-SP, SES SP - Centro de Documentação/CCD, SES-SP, SES SP - Acervo do Centro de Documentação/CCD, SES SP - Instituto Adolfo Lutz, SES-SP, SES SP - Acervo Instituto Adolfo Lutz | ID: lil-616837

RESUMO

O tucupi, produto amplamente consumido pela população do norte do Brasil, é obtido por meio de fermentação e cocção da manipueira, que é um subproduto da fabricação da farinha de mandioca seca. No processamento são utilizadas as raízes de mandioca que contêm elevado teor de ácido cianídrico (HCN), as quais quando ingeridas causam sério dano à saúde. No presente trabalho foram quantificados os teores de cianeto total e livre durante as etapas de processamento da manipueira desde a obtenção até a produção do tucupi. Além disso, foram determinados pH, acidez total titulável e teor de sólidos solúveis durante todas as etapas de processamento. A manipueira recém-extraída apresentou valores de 227,8 mg HCN/L de cianeto total e 46,6 mg HCN/L de cianeto livre. Após as etapas de fermentação houve decréscimo no teor de HCN, e o produto final (tucupi) apresentou valores de 37,1 mg HCN/L de cianeto total e 8,9 mg HCN/L de cianeto livre. Quanto aos demais parâmetros, os valores encontrados foram: pH (3,6), acidez total titulável (12,3 meqNaOH/100 mL) e sólidos solúveis (8,1 ºBrix). No presente estudo, o tucupi não apresentou valores elevados de cianeto total e livre após aplicação do processo de fermentação e cocção da manipueira.


Assuntos
Cianeto de Hidrogênio , Fermentação , Manihot
16.
Ciênc. rural ; 41(4): 592-598, abr. 2011. ilus, tab
Artigo em Português | LILACS | ID: lil-585992

RESUMO

O objetivo deste trabalho foi determinar a concentração de polifenóis totais, flavonóides, vitamina C e carotenóides totais em 61 acessos de banana pertencentes ao Banco Ativo de Germoplasma de bananeira da Embrapa Mandioca e Fruticultura. Foram detectadas diferenças significativas para todas as características analisadas por meio da análise de variância. A média para os teores de polifenóis totais entre os 61 acessos de banana foi de 38,06mg 100g-1, com variação de 12,51mg 100g-1 para o triplóide 'Torp' a 257,80mg 100g-1 para o tetraplóide 'Teparod'. A média para flavonóides foi de 2,09mg 100g-1, variando de 0,85mg 100g-1 ('Maravilha' AAAB) a 6,63mg 100g-1 ('Teparod' ABBB). Para vitamina C, a média foi de 21,60mg 100g-1, variando de 8,60mg 100g-1 (tetraplóide 'Bucaneiro') a 76,82mg 100g-1 (tetraplóide 'Teparod'). A média do teor de carotenóides totais foi de 4,34mg g-1, variando de 1,18mg g-1 ('Champa Madras', triplóide ABB) a 19,24mg g-1 ('Saney', triplóide AAB). Os diplóides Modok Gier e NBA-14 apresentaram, respectivamente, quatro e cinco vezes mais carotenóides totais que as cultivares do grupo Cavendish ('Nanica', 'Willians' e 'Lacatan'). Esses resultados permitem concluir sobre a possibilidade da obtenção de cultivares com altos níveis de compostos funcionais por meio de cruzamentos e seleção. Cultivares com este perfil têm potencial como alimento funcional, ajudando a prevenir doenças, por meio da neutralização de radicais livres.


The objective of this research was to determine the concentration of polyphenols, flavonols, vitamin C and carotenoid and in 61 banana accessions from Musa germplasm collection from Embrapa Cassava and Fruits, Brazil. Was detected significant differences for all characteristic analyzed in ANOVA. The average for polyphenols among the 61 accessions was of 38.06mg 100g-1, with variation of 12.51mg 100g-1 for the triploid 'Torp' to 257.80mg 100g-1 for the tetraploid 'Teparod'. The average for flavonols was of 2.09mg 100g-1, ranging of 0.85mg 100g-1 ('Maravilha' AAAB) to 6.63mg 100g-1 ('Teparod' ABBB). The average for vitamin C was of 21.60mg 100g-1, ranging of 8.60mg 100g-1 (tetraploid 'Bucaneiro') to 76.82mg 100g-1 (tetraploid 'Teparod'). The average of the total carotenoids was of 4.34g g-1, ranging of 1.18g g-1 ('Champa Madras', triploid ABB) to 19.24g g-1 ('Saney', triploid AAB). Diploids Modok Gier and NBA-14 exhibited 4- and 5-fold increased carotenoid content in comparison to the representatives from the Cavendish group ('Nanica', 'Willians' and 'Lacatan'). These results allow ending about the possibility of the obtaining new cultivars with high levels of functional compositions through crossings and selection. Cultivar with this profile has potential of neutralizing free radicals and to prevent diseases.

17.
Acta amaz ; 40(1): 221-226, mar. 2010. ilus, graf
Artigo em Português | LILACS, VETINDEX | ID: lil-546978

RESUMO

O objetivo deste trabalho foi quantificar a concentração de cianeto total durante as etapas de produção da farinha de mandioca dos grupos seca e d'água. Em relação à farinha seca, a concentração de cianeto total na raiz de mandioca diminuiu de 160±11,8 mg HCN/kg para 149±12,3 mg HCN/kg após a trituração, 68±2,5 mg HCN/kg após a prensagem e chegando a 5±0,2 mg HCN/kg no produto final, após o processo de torração. Na produção da farinha d'água, a raiz de mandioca apresentava teor de cianeto total de 321±21,6 mg HCN/kg e durante o processo de fermentação da raiz, o teor de cianeto total nas primeiras 24 horas de fermentação era de 297±2,7 mg HCN/kg chegando a 64±2,3 mg HCN/kg após 96 horas em repouso no tanque. Após trituração e prensagem da massa fermentada, os valores diminuíram para 50±0,6 e 36±0,4 mg HCN/kg, respectivamente, obtendo-se no produto final a concentração de 9±0,1 mg HCN/kg, sendo evidenciado a eficiência do processo de destoxificação em ambos os processamentos.


The aim of this work was to quantify the total cyanide concentration during the production stages of cassava flour from dry and water groups. In relation to dry flour, the total cyanide concentration in the cassava root reduced from 160±11.8 mg HCN/kg to 149±12.3 mg HCN/kg after grinding, 68±2.5mg HCN/kg after pressing and 5±0.2 mg HCN/kg was obtained in the final product after the roasting process. For the water flour production, the cassava root showed 321±21.6 mg HCN/kg total cyanide content, and during the fermentation process, the total cyanide content for the first 24-hour fermentation was from 297±2.7 mg HCN/kg reaching 64±2.3 mg HCN/kg after resting in a pool for 96 hours. After grinding and pressing the fermented roots, the values lowered to 50±0.6 and 36±0.4 mg HCN/kg, respectively. A concentration of 9±0.1 mg HCN/kg was obtained in the final product, evidencing the detoxification process efficiency in both processings.


Assuntos
Manihot/toxicidade , Manihot/química , Cianeto de Hidrogênio/análise , Padrão de Identidade e Qualidade para Produtos e Serviços
18.
Genet. mol. biol ; 32(1): 96-103, 2009. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-505774

RESUMO

The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 µg.g-1, and ranged from 1.06 µg.g-1 for the triploid Nanica (Cavendish group) to 19.24 µg.g-1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 µg.g-1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.


Assuntos
Carotenoides/análise , Variação Genética , Musa/genética , Marcadores Genéticos , Genótipo , Polimorfismo Genético , Técnica de Amplificação ao Acaso de DNA Polimórfico
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